Friction draft-gear.



N. 869,269. PATENTED OCT. 29. 1907.

I SIMPSON FRICTION DRAFT GEAR.

APPLICATION IILBD JAN..1o. 1907.

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i ISAAC SIMPSON, OF WILMERDING, PENNSYLVANIA, ASSIGNOR OF ONE-EIGHTH TO HARRY C. LOUDENBECK, OF WILKINSBURQ. PENNSYLVANIA.

FRICTION DRAFT-GEAR.

No. 869,269. Specification of Letters Patent. i Patented Oct. 29, 1907.

Application filed January 10, 1907. Serial No. 351,728.

To all whom it may concern: against a division plate or partition 11 which may be Beit known that 1, ISAAC SIMPSON, a subject of the provided witha nib 11a accommodated by oneV end of King of England, residing at Wilmer-dingl in (he county the smaller posterior spring l0. -On the other side of 55 of Allegheny and State of Pennsylvania, have invcntthe division plate 11, there is mounted 'the anterior i 5A ed certain new and useful Improvements in Friction spring 12, the coils of which may be square in cross 'Draft-Gears, of which the following is a specification. section or rounded if desired, although I preferably', n This invention has for its object an improved conemploy the square formation illustrated in the accomstruction of friction draft gear which will combine toa panying drawings. At its outer end, the` anterior 60 Y A i n high degree the characteristics of simplicity of strucspring 12 bears againstthe follower plate 5. v

ture, durability, and efficiency in dissipating or ab- Surrounding the anterior spring 12 are fonr cnter ...v sorbing the severe buffs and stresses that are incidental wedge blocks 13, which almost entirely encompass`- l i 'to the handling of railroad cars. said spring as best seen in Fig. 3. Each of these blocksy With this object in view, the invention consists in is provided with a concave side 11i-fitting the spring 'certain constructions, arrangements and combinaand with an opposite tapered side 15,.and the blocks" ltions ofthe parts hereinafter fully described and parare arranged with the tapers facing each other, -as best f zticularly'pointed out in the appended claims. seen in Fig. 1. In the normal position of the partei-th .F0'1" a full understanding of the invention and the proportions are such'that the blocks 13 lie fins-l1V g merits thereof and alsd to acquire a knowledge of -the the ends of the :spring 12 at the bases of said-'blocks t details 'of construction of vthe means for effecting the while their tapered ends or opposite edges-ares1ightly result, reference is to be had to the following descripspaced from each other". :Two lateral `or outside wedge tion and accompanying drawings, in which: blocks 1G embrace the four center wedge'blocksbe- Figure 1 is a horizontal sectional view of my iintween them, and each of these outside wedge-blocks proved friction draft gear, a portion of the two center is provided with two wedge sloping faces Ydesignated" 75 sillsof aiailroad car and the end of the door and its 17 and 18, respectively, and adapted to bear against bncomitant parts being shown in top plan view; Fig. 2 the tapered sides of the blocks 13, while the opposite or sas'ide elevation of my improved gear; Fig. 3 is a outside face of each block 1G is slightly tapered,` as in-v ransverse sectionalv view on the line n n: of Fig. 1; dicated at 19 and as best illustrated in Fig. 6. i.

Liis a detailiperspective view-ofone of the center Embracing the outside or lateral wedge block 16 are 8 wedge b1ocks;Fig. 5 is a similarview of one of the latthe friction plates. 20, each of which is secured rigidly .wedge blocks; Fig. 6 is a detail sideview of the and preferably in a detachablfmanuer"within Vthe l `ei'Fig. A7 is a detail perspective view of one of the outer or front end of the housingvS. In the present iIiv tion' plates; Fig. 8 is a detail edge view of said plate; stance this means of connection is comprised by a boss a dgFig. 9 isa detail perspective View of the division 21 -formedI on' the friction` plate and fitting `within a 85A- "t'e or :partition `employed between the posterior socket in the housing as seen in Fig. 1 These friction 5f Ispring and the anterior spring. plates are made detachable, so that they may be renorresponding and like parts are referred to in the moved whenever necessary and be replaced by others,` --Vfollowing description and indicated in all the views of or so that linersl may be inserted between them and .the-'drawings by the same reference characters. the housing to compensate for any wearthat might'rV 90, he drawings,l the numeral 1 designates thetwo sult from long continued use of the draft gear:4 j, 40 een er sills of a railroad car, 2 designates the draw bar. In describing the practical operation of myimproved `bile end of -which is l secured theA usual tail-strap or friction draft gear, itis of course understood that-'infin yokef, and 4 and 5 designate, respectively, two foling stresses, the rcar'followcr plate4 moves ixvifarcis:tht lower plates mountedwithin said yoke, and adapted front followerplate 5, whlcin buiiing stressesgtheh'o'li'rg) oabiit against the two-pairs oiabutment blo'clljs G and follower plate movestwardsthe rear fllowenplatefl 'lrespectively, as shown bestin Fig. 1. a This relative movementof the follower'plat'esiresults'in i n .-Withinthe tail-strap cryoke 3, apreferablyrectanthe consequent compression of the gear and uponstadtv l lilarlionsing 8 is mounted. Within this housingare" compression, pressure is brought to bear simultaneously-f 'f'the posterior springs 9 and ,'10, on' of which incloses the upon thc outer ends ofthe bases of the outergmogiticnter 1:00 -o t lier, and biiefof 'Whichis'fprefo'rably considerably wedge blocks .13, and likewise uponthe "l 'dargeip thantheothergfas, show.4 'lhese springs9.and,I ofthe anterior spring 12' The resiliency of this ante- 1 :"g `one v.end fag'ainst the bottom or outer. endf rior spring 12 causes the. center wedgehlocks 13 to tend of ,the flribusing 8, whileat ltheir other ends theybear tomove longitudinally towards each- Othe Owing t o the force resulting from the resistance of pressureexerted on posterior springs 9 and 10 pressing against divisionA plate l1., it is manifest that a solid resistance is offered at the inclined surfaces 15 of the center wedge blocks 13 from the movable lateral or outside wedge blocks 16, and consequently a powerful centripetal pressure is brought to bear on the outside of the coils of the anterior Spring 13, as the said outside wedge blocks move longitudinally on the friction plates 20 rigidly secured within the rectangular housing 8 and the parts thereby being forced into a more circumscribed area. The resistance of this pressure or radial compression of the outside of the coils of anterior spring l2 forces the center wedge blocks 13 to move upon the inclined surfaces 1.7 and 18 of the outside wedge blocks 16, and iu a direction away from each other longitudinally. This movement of the center wedge blocks 13 away from each other longitudinally is accompanied by the lengthening of the anterior spring l2 which is consequent upon or effected by the radial compression that is exerted by the center wedge blocks during the compression of the gear and the resistance to such radial compression brings direct pressure to bear upon the center wedge blocks 13 and by transmission to the lateral wed ge blocks 16. The anterior spring 12 finds space whereby its. lengthening is permissible, becauselthe longitudinal resistance offered by the posterior springs 9 and 10 upon the outer wedge blocks 13 is less than the lateral resistance offered by the anterior spring 12. Hence the center wedge blocks must move apart longitudinally in order to allow thc ac- Commodation of the parts when compressed into a smaller area, and the distance increases between the front follower 5 and the division plate 1l, thus there is no obstruction offered to the lengthening of the anterior' spring 12, and in fact, it is assisted in its lengthening by the said movement apart of the center wedge blocks, While said center wedge blocks are simultaneously compressing the anterior spring radially and moving apart longitudinally. The function performed by the posterior springs 9 and l0 in the compression of the gear is two-fold, namely, they admit of the completo traverse ofthe device, and they also control the radial compression of the anterior spring l2 by admitting of increased action other than that required in an actual travel of the gear, while at the same time, such posterior springs are not in any frictional contact radially with the friction parts. Pressure is also transmitted at the outer tapered faces 19 of the lateral wedge blocks 16 to the friction plates 20 between which, by continued compression friction is produced.

The traverse is ended obviously, when the outer end of the housing 8 and the follower plate 5 contact with each other,'and upon the removal of the pressure from the draft gear, the recoil of the anterior spring l2 releases the pressure of the frictional parts and the posterior springs 9 and l0 force said frictional parts back again to a normal or complete released position.

From the foregoing description in connection 'with the accompanying drawing, it will be seen that l have provided an improved friction draft gear in which the pressure is produced on stationary friction plates in the movement of the wedge blocks upon the same and is not produced between the outside of the coils of the anterior spring and any friction wedge elements. In my device, the hollow lrictional mechanism is employed in a more circumscribed area during operation and this movement is resisted and also pressure on the wedge blocks is rcsistcd by the longitudinal action of the ordinary coil springs, to wil., the posterior springs, and said springs heilig in no circumferential Contact with the wedge. members. The radial resistance of the anterior spring 12, it will be seen, is exerted to force the center wedge blocks 13 to move apart longitudinally and this movement is resisted by the posterior springs. Consequently a powerful pressure is exerted upon the lateral wedge blocks 16 in the movement of which upon' the friction plates produces the friction. The advantage of this arra n gement. and conscq nent operation of the parts resides in the fact fhat't'hc anterior spring is not subjected to the fatal deli-ct of being compressed radially and longitudinally at the same time and without com- A pensating for releasing it from such position, because the yielding of said posterior springs permits the anterior spring to elongate, thereby insuring its safety against breakage and relieving it from any undue strain d nring the operation of the gear. Then again, the friction parts are early brought into operation by reason of a.

as new is:

1. ln :i friction draft gear, the combination with a drawbar. :ind its rclntivcliv movable follower plates, of a series of coil springs interposed between said plates, wedge blocks surrounding one of said springs, the other spring being free from frictional contact with said wedge blocks` and means for controlling the. radial compression of said snrifouiuled spring by the longitudinal resistance of the other through the instrumentality of said wedge blocks.

2. ln :1 friction draft gear. the combination of a draw bar and its relatively movable follower plates, of anterior :ind posterior springs, n housingr in which said springs are contained. n division plate between the anterior and posterior springs. wedge blocks surrounding the anterior .spring and located between lthe division plate and the front follower plate, friction plates secured in said housin;r :ind bearingr against the wedge blocks, and means whereby radial compression of the anterior spring is controlled b v the longitudinal resistance of the posterior spring :ind the conction between the wedge blocks and said friction plates.

2:. ln a friction draft gear, the combination with a draw bar :ind its front and reni' follower plates, of anterior and posterior springs interposed between said plates, a housing within which said springs are contained, a division plate between tln` anterior and posterior springs, center wedge blocks surrounding said anterior spring with their wedge surfaces facing each other, said blocks being located berwccn the division plate and the front follower plate, n lateral wedge block having oppostelv sli'ipingl faces adapted lo engage the wedge surfaces of. the center wedge blocks, :ind -friction plates' secured rigidly within the enter end of the housing and adapted to bear against the outer side oi' the lateral wedge blocks 4. lu :i friction draft'. gear, the combination with a drawbar and its front and rear follower plates. of anterior and posterior springs between said plates, a housing within which said springs are contained, a division plate between the anterior and posterior springs, center wedge blocks izo l of said lateral Wedge blocks, the coacting faces of the lat- 5 eral wedge hlocks and the friction plates being correspondingly tapered.

In testinumy whereof I atlx my signature in presence of two witnesses.

ISAAC SIMPSON. [1.. s.] Witnesses Elnlifxh SInrsON. 

